Several forms of acute human diarrheal disease due to enterotoxins may be curtailed by antibacterial therapy and diminished by enhancement of active glucose absorption but no effective pharmacologic control of the fluid secretory process has been achieved. Utilizing pure 3H-choleragen and 3H-choleragenoid, the binding characteristics of the pure toxin and its inactive fragment will be defined utilizing hamster intestinal microvillous membranes. The inhibitory effect of a variety of agents, including (1) plant lectins, (2) fruit pectins, (3) peptide antibiotics and ionophores will be studied in this in vitro system, as well as in the live hamster model of enterotoxin induced secretion which we have developed. BIBLIOGRAPHIC REFERENCES: Maimon, H., Mitch, W., Banwell, J.G., Hendrix, T.R.: Control of enterotoxin induced secretion by the polypeptide antibiotic, Polymyxin. Johns Hopkins Med. Journal 138:82-90, 1976. Banwell, J.G., Hanke, D., Lepot, A.L., Giannella, R.A.: $ Characteristics of Polymyxin binding to brush border membranes and its relationship to intestinal adenylate cyclase. Gastroenterology 70:A108/966, 1976, Abstract.